Fire-alarm.



W. H. BOWMAN.

HR; ALARM. APPLICATION FILE D MAY'28. I915.

1,162,020, I Patented Nov. 30, 19R

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' W'ALTER H. BOWMAN, G}? BBIDGEPORT, CONNECTICUT.

FIRE-ALARM.

Specification of Letters Patent.

Patented Nov. 3%. 1915.

T 0 all whom it may concern Be it known that I, TALTER HI. BOWMAN,

ll denotes a depending flange at the edge of the cap which in the awenibled-position a citizen of the United States, residing at lies at a slight distance from the case, leav- Bridgeport, county of Fairfield, State or" Connecticut, have invented an ln'iprovenient in l ne-Alarms, of which the following is a specification.

This invention has for its object to provide a fire alarm adapted for general use and especially adapted for use in connection with the telephones of an independent system, as in hotels, apartments, factories, school houses, &c. f

A further object of the invention is to produce a fire alarm which shall be durable and reliable, will not require attention and shall be so inexpensive to produce as to place it within the reaclrofthose using a small tenement or even a single room, and so easy to attach that any person, skilled or unskilled, may installit with no other tool than a screwdriver.

With-these and other objects'in view, I have devised the novel fire alarm which I will now describe, referring to the accompanying drawing forming. a part of this specification and using reference characters to indicate the severalv parts:

Figure 1 is elevation showing the application of the invention to an ordinary desk telephone; Fig. 2 an elevation of the case withthe cap and retaining material in section; 3 a similar view with the case in section, showing the spring in elevation; Fig. 4: a section of a slightly variant form of cap. Fig. 5 a plan view of the alarm and a clamp for attachment to a desk telephone; Fig. 6 an elevation of the alarm and a bracket for securing itto a well or fixture.

My novel alarm comprises simply a case made of inetalor any suitable material open at one-end, a spring in said case, an alarm cap for the closed end having depending-'- ilange, and low melting material between the flange and the case for retaining the cap in placeiat all temperatures below its melting! point; Should the temperature u l I I I 1 of the anbe raised snliicientiy to melt the retaining material, the spring will lift the cap and produce an alarm which may be caused by any suitable auxiliary means.

10 denotes the case. 11 the spring and 1:2

the cap which is preferably provided with a central depression or. thickened portion 13 which passes into the open end of the case and eentersthe cap thereon.

4 hatched or otherwise roughened for engage ment by the retaining material.

It should be understood that by the term melting I mean a sufiicicnt softening of the retaining material to weaken it so that the spring Will overcome the resistance thereof and dislodge and raise the cap.

In Fig. 1, I have illustrated the use of my novel alarni'in connection with an ordinary desk telephone. This use of the alarm will be found ery serviceable in hotels, apartmerit houses, factories, school houses, or wherever there are a number of rooms, apartments 01: floors using a central telephone system having an attendant.

1! denotes the standard of a telephone, 17 the spring-controlled arm and 18 the receiver which is hung upon arm and retains the arm in the circuit closing; position againstthe spring, whicnis not shown, as it speeiiicalh/ forms no portion of the present invention. As an inexpensive and convenient means of securing the alarm to the standard of the telephone, I provide a spring clamp comprising eye 19 which grips the case closely and arms 20 adapted to inclose the standard. of a telephone and a nut and screw indicated by 21 by which the clamp with the alarm held thereby is se cured in place.

The operation will be obvious. A retain ing ,inaterial is of course used that will melt or soften appreciably at a predeternined temperature. When. the air in the room reaches this temperature from any cause whatever. the yielding of the retaining.

material will permit the spring to lift the can and with it the arm and receiver of the telephone which produces a signal in the centre oifice. The spring will act to retain the line open which continues the signal (in effect an alarm) until. the line is closed in at the telephone.

the form illustrate,

is held in place by a bracket-22 whici adapted for attachment to a Wall or fixture end of the case, a depending flange lying at of any kind. a distance from the case and leaving a ring- 10 v Having thus described my invention, I shaped space between the flange and the claim; case, and low-melting retaining material in 5 A fire alarm comprising a case open at one said space, by which the cap is retained in end, a s ring therein, an alarm cap adapted place and the spring held compressed. to befriiased by the spring and having a cen- In testimony whereof I affix my signature. 15 ti'al depression which passes into the open WALTER H; BOWMAN. 

